Fabrication of electric chucks



fm@ @l Nov. 13, 1945. D, F. GOTHA 2,388,737

C UC I Filed Jan. l5, 1944 Y .i li Ik Uv" yfmmj- 4 Patented Nov. 13, 1945 UNITED STATES PATENT OFFICE FABRICATION F ELECTRIC CnUCKs Daniel F. Gotha, WorcesterjMass., assgnorto O. S. Walker Co. Inc.,` Worcester, Mass., a corporation of Massachusetts Application January 15, 1944, Serial No. 518,312

(Cl. 2li-155.5)

4 Claims.

This invention relates to a method for fabricating chucks and more particularly the invention y concerns the fabrication of chuck bodies for receiving the coils of electric chucks.

Objects of the invention include the provision of a method of fabricating an electric coil body for a chuck from a single sheet or plate of iron and avoiding the conventional cast structure and also the method of building up a comparable chuck body by the use of separate bars welded together.

Further objects of the invention include the provision of a method of fabricating a chuck body part for receiving electric coils by cutting out cores from a sheet or plate of iron, removing the cores from the plate, applying the remainder of the iron plate to a conventional bottom plate and positioning the cores within the holes formed by the removal of the cores from the body plate,

land placing the electric coils about the cores in the usual manner.

Another object of the invention is the provision of a method of making a chuck coil body by burning cores from a sheet or plate of iron at desired locations, removing the burnt-out cores, enlarging the holes occasioned by the formation of the cores in a desired pattern, thus forming an integral one-piece grill-like plate, securing said grill-like plate to a bottom plate as by welding, securing the said cores substantially centrally of the enlarged holes, and then applying the electric coils in the usual manner.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing in which:

Fig. 1 is a perspective view of an iron sheet or plate and illustrating successive steps in the fabrication of a chuck according to the invention;

Fig. 2 is a top plate View of the chuck body completed but before the application of the electric coils; and

Fig. 3 is a section on line 3-3 of Fig. 2 and showing a top plate.

In carrying out the invention a sheet or plate of iron I 0 having substantially the dimensions required in the finished coil-holding body part of the chuck is cut along lines I3 to remove cores I2, as by means of a llame I4 or by other conventional means. The cores are cut and removed from predetermined locations which determine the approximate nal location of the cores in the chuck body as illustrated at I 6 wherein the cores have been cut and removed. It is understood that the cutting of the cores proceeds throughout the area of plate I0 in a predetermined Dattern and spacing, and this pattern andspacing will assume whatever form is desired in the nished chuck.

When the cores I2 have been removed from the plate I0, leaving a series of holes I6, the latter are enlarged by any desired means such as further burning or milling, etc., to form core receiving holes as illustrated at I8. These holes conform in general to the oval shape of the conventional chuck coils and may be hollowed out at the ends as at -20 for this purpose. When this operation has been completed the coil-receiving body is iinished and this body comprises a grill-like plate which is all in one piece and comprises the remainder of plate I0. For illustrative purposes plate I0 is shown as beveled off around its lower edge as at 22 for a purpose to be described.

Bottom plate 24 is utilized to support the grilllike plate and as indicated at 26 the plate may be welded to the bottom plate 24 completely about the periphery thereof. The cores I2 are then positioned centrally of each of the core-receiving holes I8 as illustrated in Fig. 2 and the cores may then be secured to the bottom plate as by tack welding at 2B. The chuck is now substantially complete except for applying the electric coils, not shown, around the cores and securing the top plate 30 as by any desired means, preferably by screws or the like for removability.

The top plate may be of any desired construction or configuration as long as the correct registry is made with the cores and the remaining parts of plate Ill and it will be seen that the construction provides that the cores I2 are exactly the same height as the thickness of plate IIJ due to the manner in which the cores are produced. Hence no machining of top or bottom surfaces of plate I0 and the coils is necessary and a finish'- ing grinding operation is all that remains to provide good contacting surfaces between the plate I0 and cores I2 with bottom plate 24 and top plate 30. Of course, lead wire apertures must be machined out, but this is conventional in the art.

Having thus described my vinvention and the advantages thereof, I do not wish to be limited to the details h'erein disclosed, otherwise than as set forth in the claims, but what I claim is:

l. A method of fabricating chucks comprising removing cores from a plate in a predetermined pattern in the plate, securing the plate and the cores to a bottom plate, with the cores in spaced relation to the walls of th'e holes formed by the removal of the cores, and applying electric coils surrounding the cores.

2. A method of fabricating chucks including the steps of removing cores from a. plate in a predetermined pattern by cutting out the cores completely through the body of the plate, and securing the plate and cores to a bottom plate with' the cores located substantially centrally in the holes in the rst named plate formed by the removal of the cores therefrom.

3. A methodioflffabricating ch'ucks :comprising: removinga series of cores from' an'ion plate by cutting the plate on closed paths dening the. cores, enlarging the holes formed in the plate by the removal of the cores, securingthef:coresgand' the remainder of the plate to a. bottom plate with the cores located substantially?centrallyin'tliei15v enlarged holes, and applying electric coils surrounding the cores.

4. A method of fabricating electric chucks including the steps of forming cores by burning completely through an iron plate on closed paths so that the cores have a dimension equal to th'e thickness of the plate, removing the cores, enlarginghe holes formed. by. the .burning step to aisize capables oreceiyingelctifie."coils, securing'the plate to a bottom plate,'se'curing a core tothe bottom plate substantially centrally of each ofsaid enlarged h'oles and applying electric coils imtheeusuallnanrrer.

DANIEL F. GOTHA. 

